Laccase mediated conjugation of heat treated β-lactoglobulin and sugar beet pectin

Laccase, an oxidative enzyme, was used to catalyze the hetero and homo covalent conjugation between ferulic acid in sugar beet pectin (SBP) and tyrosine in heated β-lactoglobulin (H_BLG). The conjugation of SBP and H_BLG was confirmed by peak position using size exclusion chromatography, multi angle laser light scattering, refractive index, and UV detection. H_BLG, pre-treated with laccase, eluted at an earlier volume with greater UV280 absorbance than non-laccase treated dispersions. Tyrosine decreased in H_BLG that contained laccase treated SBP samples. Heat enhanced exposure of tyrosine in BLG and improved conjugation with SBP by laccase. H_BLG·SBP conjugates with laccase had improved solubility than laccase untreated dispersions at pH values near the isoelectric point of BLG.